feat(query): add overview() for project-aware session/memory discovery

Resolves current project from cwd, lists all known projects with session
  and memory counts, and returns the current project's recent sessions and
  memories in one call. Enables the agent to orient itself at the start of
  a retrieval without multiple exploratory queries.

references/query-patterns.md

@@ -4,6 +4,37 @@ These are copyable CodeAct patterns for `runtime.mjs --query` scripts, plus one
 `--remember` registration pattern. They are not new APIs. Adapt them to the
 user's scope and return compact evidence.
 
+## Orient Before Retrieval
+
+Use `overview()` when the current project or available scopes are unclear. Treat
+the result as a map, not evidence; follow up with `memories()`, `search()`,
+helpers, or `sql()` for facts.
+
+```js
+const map = overview({ limit: 6 });
+return {
+  current: map.current,
+  current_project: map.current_project && {
+    project: map.current_project.project,
+    session_total: map.current_project.session_total,
+    sessions: map.current_project.sessions.map(s => ({
+      id: s.id,
+      title: s.title,
+      branch: s.git_branch,
+      ended_at: s.ended_at,
+    })),
+    memory_total: map.current_project.memory_total,
+    memories: map.current_project.memories.map(m => ({
+      id: m.id,
+      path: m.path,
+      summary: m.summary?.slice(0, 240),
+    })),
+  },
+  projects: map.projects.slice(0, 8),
+  totals: map.totals,
+};
+```
+
 ## Bounded Search To Context
 
 Use `search()` to locate candidates, then expand only the strongest hits.